How much weight can water weight be

Please don’t laugh. I am habitually dehydrated, so I’ve made it a game to drink 12 three-ounce Dixie cups of water the minute I get out of bed, so I know I’ve started my day off well hydrated.

Out of curiousity, I weighed myself before and after the other day. My scale does tenths of pounds.

The difference was exactly 2 pounds. Makes absolute sense. 12x3=36 ounces.

Water is heavy. Think about holding a gallon of milk or a case of 8oz water bottles. That’s a pretty substantial weight.

I think at the degree of weight loss we’ve both had, that the infrequent pig out is something our bodies can now cope with and readily expel, but as you say, you it clearly marks it as water weight for a few days.

In a way, I’m grateful it does, because I need that cold tingly reminder the Day After that I better not get in the habit of doing that again.

And sweetie, one day of screwing up is not a relapse. It was a good time and I sincerely hope you enjoyed yourself and didn’t have my usual Day After regrets of “Damn. If I’d known that was going to cost that many calories, I’d have spent them on something better!” 😂

Considering that I've dropped 6 pounds overnight - when that was a much larger percentage of my bodyweight compared to what you're seeing, besides - I'll say yes, 6 pounds can be water weight.

Details here:

https://community.myfitnesspal.com/en/discussion/10679961/this-never-happened-before-fun-with-weight-fluctuations#latest

Is/was it 6 pounds of water weight, in your situation? Harder question. 🤷‍♀️

Also, I agree with others: If I eat a massively unusual amount, thousands above my maintenance calories, I don't normally see as much fat gain as the number of excess calories might imply. Things that do tend to happen in the next 24 hours: Unusual hot flashes, higher resting heart rate . . . .

I've eaten 2 or more times my maintenance calories in a day, quite a number of times, in the 5+ years I've been in weight maintenance . . . staying at a healthy weight the whole time, though I won't deny some ups and downs well within the healthy range, over that timespan.

If you want some science on why an exceptionally high day, rarely, may not resulted in the fat gain equal to 1 pound for each 3500 excess calories, look up Stephanie Buttermore's two YouTube videos about the 10,000 calorie challenge, one about the eating, one about follow-up lab testing. I'm not going to link the videos here because I don't know how to make them links rather than (annoying) in-line video, but they're easy to find. Make sure you get her videos, not someone else's retrial, review or commentary on hers.

Yup. 4 - 5 lbs is not unusual for me, and 6 or 7 was possible back when I weighed ~205.

I get this type of question from my clients often.
Realistically 5 lbs is not earth shattering failure. I feel the effect when I allow myself to have a reward meal and allow myself to have bread and cheesecake.
Question: How often are you weighing in? I recommend no more than 1-2 times a week because your weight will swing 3-5 lbs from one day to the next.
If it is water weight, you got back on track with intake and exercise water weight will shed within a couple days to a week. If you still have the weight after a week then you need to look at your recent nutrition and exercise and make appropriate adjustments.
You can attempt a 24 our fast to reset your system as well; its not as tough as it sounds. If you have never done a 24 hour try doing a 16 hour a couple times to warm up. DO NOT fast more than two - three days a week and only once a month. this avoids under-nutrition, and your body getting used to it. If you are diabetic monitor your glucose throughout the fast. You can have zero calorie fluids like water, coffee, tea, unsweetened Jello, will help with cravings. I recommend you limit drinks with sodium and potasium like Gatorade to 1 liter/quart per day to avoid retaining water.
Your fast starts after you eat dinner. I recommend a low carb day before fasting and Finnish eating at least 2 hours before bed that will start your fast. You sleep 8 hours and when you wake up you are 10 hours into it. Hydrate and stay hydrated, find easy tasks to keep your mind and body active, until diner. When you do eat eat a low carb 500 calorie meal, no desert. Just like the night leading up in bed 2 hours after eating. Reset complete.
Stay away from the voodoo cleansing drinks all they will do is dehydrate you.
Never allow yourself cheat days because only one day can easily destroy weeks worth of work. Instead plan a single reward meal.
This involves strategy because EVERYTHING has to be on point, only once every two weeks You may go over on one macro carbs or sugar but try to keep the rest within range.

If I ate bad for one day my weight can jump 10+ lbs. My body retains water very easily.

Here's a deep dive I did on a particularly big water weight swing I observed
https://community.myfitnesspal.com/en/discussion/10672255/examination-of-outlying-scale-fluctuation#latest